ORIGINAL: Tony Hallo
The bottom line here is Koverall without paint weights about 1/2 oz less than Monokote , it's hard to image it will ever come out finished less than Monokote. As far as .6 oz cloth there's really no comparsion because cloth requires full sheeting while Monokote can be installed over open bays, nothing weights less than air. Each covering method has it's own merit. I would bet even the above average modeler would find it difficult to produce a fabric or glassed model weighting less than the Monokoted version.
The open bay vs. fully sheeted arguement only applies if you are building models that aren't fully sheeted. Since I like pattern planes, it isn't much of an issue for me a lot of the time. But it is true that air is pretty hard to beat on the scale. Every method has it's place. Film is good for smaller, lighter weight sport models. For bigger stuff, especially scale planes, fabric and paint are hard to beat. I am currently building a Mojo 40 and would never consider anything other than film for it. I am also designing a 40% Cassutt racer at the moment and wouldn't consider anything other than Koverall and PolyC for it. Horses for courses as it were.
Mark